Framework for temporal label switched path tunnel services

ABSTRACT

A method for establishing a temporal label switched path (T-LSP) implemented in a node in a network. The method includes receiving a path request including a time interval and a set of constraints; obtaining traffic engineering information from a first database; computing, by the node, a path satisfying the time interval and the set of constraints based on the traffic engineering information obtained; storing the time interval and the set of constraints in a second database; and instructing an ingress node of the temporal LSP to signal the temporal LSP in the network along the path computed at a start of the time interval identified in the path request and to tear down the temporal LSP at an end of the time interval identified in the path request.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of co-pending U.S. patentapplication Ser. No. 15/269,098, filed Sep. 19, 2016, by Huaimo Chen andentitled “Framework for Temporal Label Switched Path Tunnel Services,”which claims the benefit of U.S. Provisional Patent Application No.62/242,172, filed Oct. 15, 2015, by Huaimo Chen and entitled “Frameworkfor Temporal Label Switched Path Tunnel Services,” the teachings anddisclosure of which are hereby incorporated in their entireties byreference thereto.

TECHNICAL FIELD

In general, the disclosure describes techniques for software definednetworks. More specifically, this disclosure describes techniques thatallow for creating a temporal label switched paths in a software definednetwork in one or more predetermined time intervals.

BACKGROUND

Software defined networking (SDN) is a networking paradigm thatdecouples network control and forwarding functions. The decoupling ofthe control plane from the data plane allows for centralization ofnetwork control, enabling effective policy administration and flexiblemanagement. The centralization of network control facilitates variousnetwork functionalities, such as network measurements, trafficengineering, enhanced quality of services, and enhanced access control.With the growing availability of SDN-enabled nodes and protocols, manyorganizations have started deploying SDN networks.

SUMMARY

In a SDN network, a SDN controller determines routes through the networkand configures each node in the network with routing instructions. In aSDN network that employs label switched paths (LSPs) for datatransportation, a SDN controller provides a solution for creating LSPsin the network without employing Resource Reservation Protocol (RSVP).Every LSP created by the SDN controller is up forever and networkresources are reserved for the LSP forever until the LSP is deleted.However, some LSPs may not be actively carrying traffic at all time.Thus, network resources may not be used efficiently. In addition, theLSPs created by a SDN controller are typically limited to the domaincontrolled by the SDN controller and may not tunnel through multipledomains. To resolve these and other problems, and as will be more fullyexplained below, a temporal SDN (T-SDN) controller is used to createtemporal LSPs for carrying traffic at one or more particular timeintervals according to users' requests and to reserve network resourcesfor the temporal LSPs in corresponding time intervals. In addition, theT-SDN controller coordinates with temporal path computation elements(T-PCEs) to create temporal LSPs that tunnel through multiple domains.

In a first aspect, the disclosure includes a method for establishing atemporal label switched path (T-LSP) implemented in a node in a network.The method includes receiving a path request including a time intervaland a set of constraints; obtaining traffic engineering information froma first database; computing, by the node, a path satisfying the timeinterval and the set of constraints based on the traffic engineeringinformation obtained; storing the time interval and the set ofconstraints in a second database; and instructing an ingress node of thetemporal LSP to signal the temporal LSP in the network along the pathcomputed at a start of the time interval identified in the path requestand to tear down the temporal LSP at an end of the time intervalidentified in the path request.

In a first implementation form of the method according to the firstaspect as such, the method further comprises distributing current linkbandwidth to other nodes and storing changes in the current linkbandwidth in the first database.

In a second implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the traffic engineering information comprises a bandwidth for each linkin the network corresponding to the time intervals.

In a third implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the first database is a temporal traffic engineering database (T-TED).

In a fourth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the second database is a temporal LSP database (T-LSPDB).

In a fifth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,further comprising establishing an LSP without the time intervalscorresponding to the path as computed.

In a sixth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the node is a temporal software defined network (T-SDN) controller.

In a seventh implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the temporal LSP crosses multiple domains.

In an eighth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,each of the multiple domains is controlled by a separate controller.

In a ninth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the method further comprises receiving the path request from a networkadministrator.

In a tenth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the method further comprises receiving the path request from anapplication.

In a second aspect, the disclosure includes a network element includinga memory storage comprising instructions; and a processor incommunication with the memory, wherein the processor executes theinstructions to cause the network element to: receive a path requestincluding a time interval and a set of constraints; obtain trafficengineering information from a first database; compute a path satisfyingthe time interval and the set of constraints based on the trafficengineering information obtained; store the time interval and the set ofconstraints in a second database; and instruct an ingress node of thetemporal LSP to signal the temporal LSP in the network along the pathcomputed at a start of the time interval identified in the path requestand to tear down the temporal LSP at an end of the time intervalidentified in the path request.

In a first implementation form of the method according to the firstaspect as such, the processor executes the instructions to cause thenetwork element to distribute current link bandwidth to other nodes andstore changes in the current link bandwidth in the first database.

In a second implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the traffic engineering information comprises a bandwidth for each linkin the network corresponding to the time intervals.

In a third implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the first database is a temporal traffic engineering database (T-TED).

In a fourth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the second database is a temporal LSP database (T-LSPDB).

In a fifth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the processor executes the instructions to cause the network element toestablish an LSP without the time intervals corresponding to the path ascomputed.

In a sixth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the node is a temporal software defined network (T-SDN) controller.

In a seventh implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the temporal LSP crosses multiple domains, and wherein the multipledomains are each controlled by a separate controller.

In an eighth implementation form of the method according to the firstaspect as such or any preceding implementation form of the first aspect,the path request is received from a network administrator or anapplication.

For the purpose of clarity, any one of the foregoing embodiments may becombined with any one or more of the other foregoing embodiments tocreate a new embodiment within the scope of the present disclosure.

These and other features will be more clearly understood from thefollowing detailed description taken in conjunction with theaccompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this disclosure, reference is nowmade to the following brief description, taken in connection with theaccompanying drawings and detailed description, wherein like referencenumerals represent like parts.

FIG. 1 is a schematic diagram of a SDN system.

FIG. 2 is a schematic diagram of an embodiment of a temporal softwaredefined network (T-SDN) controller managing a network corresponding to acentralized model for a single domain.

FIG. 3 is a schematic diagram of an embodiment of a T-SDN controllermanaging a network corresponding to a centralized model for multipledomains.

FIG. 4 is a schematic diagram of an embodiment of a T-SDN controllermanaging a network corresponding to a hybrid model for a single domainand one set of databases.

FIG. 5 is a schematic diagram of an embodiment of a T-SDN controllermanaging a network corresponding to a hybrid model for a single domainand two sets of databases and communication with edge nodes.

FIG. 6 is a schematic diagram of an embodiment of a T-SDN controllermanaging a network corresponding to a hybrid model for a single domainand two sets of databases and communication with edge and internalnodes.

FIG. 7 is a schematic diagram of an embodiment of a T-SDN controllermanaging a network corresponding to a hybrid model for multiple domains.

FIG. 8 is a schematic diagram of an embodiment of a network node (e.g.,router) corresponding to a distributed model.

FIG. 9 is a method for establishing a temporal label switched path(T-LSP) implemented in a node in a network.

FIG. 10 is a schematic diagram of a network element according to anembodiment of the disclosure.

DETAILED DESCRIPTION

It should be understood at the outset that although an illustrativeimplementation of one or more embodiments are provided below, thedisclosed systems and/or methods may be implemented using any number oftechniques, whether currently known or in existence. The disclosureshould in no way be limited to the illustrative implementations,drawings, and techniques illustrated below, including the exemplarydesigns and implementations illustrated and described herein, but may bemodified within the scope of the appended claims along with their fullscope of equivalents.

FIG. 1 is a schematic diagram of an example of a software-definednetwork (SDN) system 100. The SDN system 100 comprises a SDN controller110 and a network 130. The network 130 comprises a plurality of edgenodes 121, shown as PE1, PE2, PE3, and PE4, and a plurality of internalnodes 122, shown as P1, P2, P3, and P4, with some or all nodesinterconnected by a plurality of links 131. The edge nodes 121 arelocated at an edge or a boundary of the network 130. The internal nodes122 are located within an area of the network 130. The underlyinginfrastructure of the network 130 may be any type of network such as anelectrical network, an optical network, or combinations thereof. Thelinks 131 may comprise physical links such as fiber optic links,electrical links, wireless links and/or logical links used to transportdata in the network 130. The network 130 operates under a single networkadministrative domain. The network 130 may employ any forwarding dataplane such as a multiprotocol label switching (MPLS) forwarding dataplane. The SDN controller 110 is communicatively coupled to all edgenodes 121 and all internal nodes 122 of the network 130. The system 100decouples network control and network forwarding functions.

The SDN controller 110 may be a virtual machine (VM), a hypervisor, orany other device configured to manage and control the network 130. TheSDN controller 110 obtains and/or maintains a full topology view of thenetwork 130. The SDN controller 110 computes forwarding paths throughthe network 130 according to the topology information. For example, theSDN controller 110 may employ a shortest path algorithm to determine apath between a source-destination pair in the network 130. Aftercomputing the paths, the SDN controller 110 sends forwardinginstructions to the edge nodes 121 and to the internal nodes 122 toinstruct the edge nodes 121 and the internal nodes 122 to forwardpackets according to the computed forwarding paths. The forwardinginstructions may be dependent on the routing protocol. The SDNcontroller 110 communicates with all edge nodes 121 and all internalnodes 122 via a plurality of communication channels 140. Thecommunication channels 140 are also referred to as controller-networkcommunication channels. In some circumstances, the communicationchannels 140 are OpenFlow channels as described in the OpenFlow switchspecification version 1.5.1 defined by Open Networking Foundation (ONF),Mar. 26, 2015.

The edge nodes 121 and the internal nodes 122 are software programmablenetwork devices configured to perform forwarding functions in thenetwork 130 according to forwarding instructions received from the SDNcontroller 110 via the communication channels 140. The edge nodes 121are further configured to function as access points or interconnectionpoints between the network 130 and other networks, which may be similarto the network 130 or different from the network 130 and may operate inother domains. For example, the edge nodes 121 may establish networkingsessions and/or services with different networks, but may not exchangetopology information across the different networks.

The network 130 may employ MPLS for data forwarding. In MPLS, datapackets are assigned labels, which are referred to as path labels orsegment labels, and the data packets are forwarded or directed on a LSPbased on the labels. To establish a LSP between a source and adestination, the SDN controller 110 computes a shortest path through thenetwork 130 for the LSP and reserves network resources such asbandwidths on the links 131 along the computed path of the LSP. Thenetwork resources are reserved for the LSP forever or until the LSP isdeleted. The SDN controller 110 assigns path labels for the LSP andconfigures each edge node 121 and each internal node 122 along the pathof the LSP. As an example, a LSP 171 traversing the edge node PE1 121,the internal nodes P1 and P2 122, and the edge node PE4 121 isestablished in the network 130. For example, the edge node PE1 121 isconnected to the source and the edge node PE4 121 is connected to thedestination. Thus, the edge node PE1 121 is referred to as an ingressnode of the LSP 171, the edge node PE4 121 is referred to as an egressnode of the LSP 171, and the internal nodes P1 and P2 122 are referredto as transit nodes of the LSP 171. Since the SDN controller 110 managesall network and label resources, the network 130 is not required toemploy any Resource Reservation Protocol (RSVP) or label distributionprotocol (LDP).

In a large-size SDN network, the management of all resources in thenetwork may be complex and the number of communication channels 140 maybe large. Thus, the design and implementation of the SDN controller 110may be complex and costly. In addition, all edge nodes 121 and allinternal nodes 122 in the network 130 are required to be upgraded toSDN-enabled nodes. For example, hardware-based network devices arerequired to be replaced with programmable or software programmablenetwork devices. Thus, the deployment of the system 100 may be timeconsuming and costly.

Disclosed herein are various embodiments for creating a temporal LSP ina SDN network in one or more predetermined time intervals. The temporalLSP is scheduled to carry traffic in the predetermined time intervals.Some examples of traffic scheduling in a temporal LSP are disclosed inU.S. patent application Ser. No. 15/187,384 filed Jun. 20, 2016, byChen, et al., entitled “Elegant Temporal Label Switched Path TunnelService Controller,” the teachings and disclosure of which are herebyincorporated in their entireties by reference thereto. The disclosedembodiments employ a temporal SDN (T-SDN) controller or a temporal node(e.g., a switch, router, bridge, server, a client, etc.) configured toestablish a temporal label switched path (T-LSP) through a network. Insome embodiments, the T-SDN controller is able to communicate with othercontrollers outside the network to create and/or delete a temporal LSPthat crosses multiple domains. In some embodiments, the T-SDN controlleris equipped to create both a temporal LSP, which utilizes timeintervals, and a non-temporal or normal LSP, which does not utilize timeintervals. The temporal LSP and the normal LSP may be used concurrentlyto transport traffic. In some embodiments, the T-SDN controller managesedge nodes and/or intermediate nodes in the network. In someembodiments, the T-SDN controller instructs nodes in the network to makelabel reservations instead of the reservations being made by the T-SDNcontroller. The disclosed embodiments offer a variety of benefitsincluding, for example, an increase in the efficiency of networkresource usage, an ability to provide and/or reserve a tunnel service inadvance, and the ability to meet new requirements of Internet ServiceProviders (ISPs) such as service scheduling and calendaring.

FIG. 2 is a schematic diagram of an embodiment of a SDN system 200including a T-SDN controller 210 configured to manage a network 230. Theschematic diagram depicts a centralized model for a single domain. TheSDN system 200, the T-SDN controller 210, and the network 230 in FIG. 2are similar to the SDN system 100, the T-SDN controller 110, and thenetwork 130 of FIG. 1. As shown, the network 230 contains a plurality ofedge nodes 221 (e.g., ingress nodes or egress nodes) and internal nodes222 (e.g., intermediate nodes) connected by links 231. The edge nodes221, the internal nodes 222, and links 231 of FIG. 2 are similar to theedge nodes 121, the internal nodes 122, and links 131 of FIG. 1.

In an embodiment, the T-SDN controller 210 is configured to establish atemporal LSP through the network 230. To do so, the SDN controller 210communicates with the edge nodes 221 and the internal nodes 222 via aplurality of communication channels 240. The T-SDN controller 210includes a temporal label switched path (T-LSP) manager 202, a temporalconstrained shortest path first (T-CSPF) element 204, a temporal trafficengineering database (T-TED) 206, a temporal label database (T-LDB) 208,a temporal LSP database (T-LSPDB) 212, and a network interface (In).

The T-LSP manager 202 is configured to receive a path request from, forexample, an application or network administrator requesting an LSP beestablished. In an embodiment, the path request includes time intervalsand a set of constraints for the LSP. As will be more fully explainedbelow, the T-LSP manager 202 establishes a path using the T-CSPF element204. The T-LSP manager 202 also reserves or releases bandwidth in theT-TED 206 corresponding to the time intervals contained in the pathmessage. The T-LSP manager 202 creates or deletes the LSP along acomputed path in the network 230 by sending a request to one or more ofthe nodes 221, 222 in the network 230. In addition, the T-LSP manager202 updates a status of the LSP to up or down and notifies theapplication, the user of the application, or network administrator ofthe status. In an embodiment, the T-LSP manager 202 is operably coupledto the network 230 through network interface (In).

The T-CSPF element 204, which may be generically referred to as atemporal path element, is operably coupled to the T-LSP manager 202. Inan embodiment, the T-CSPF element 204 is in communication with the T-LSPmanager 202 through an interface (Ia) and in communication with theT-TED 206 through an interface (Ie). The T-CSPF element 204 isconfigured to receive the path request from the T-LSP manager 202,obtain traffic engineering information from the T-TED 206, compute apath satisfying the time intervals and the set of constraints based onthe traffic engineering information obtained, and provide the path ascomputed to the T-LSP manager 202. In an embodiment, the trafficengineering information obtained from the T-TED 206 includes a bandwidthfor each link 231 in the network 230 corresponding to the timeintervals. In an embodiment, the T-CSPF element 204 is configured tocompute a path for the LSP in a single domain (e.g., network 230).

The T-TED 206 is configured to maintain traffic engineering information(e.g., bandwidth) for each link 231 with time intervals in the network230. The T-TED 206 is also configured to provide the traffic engineeringinformation to the T-CSPF element 204 for use in computing the path uponrequest by the T-CSPF element 204. The T-TED 206 is operably coupled tothe T-LSP manager 202 through an interface (Ib). The T-TED 206 isconfigured to reserve bandwidth corresponding to the path during thetime intervals upon request by the T-LSP manager 202. In an embodiment,the T-TED 206 is also operably coupled to the network 230 throughinterface (In).

In an embodiment, the T-TED 206 may be updated by the following events.When a temporal LSP with a number of time intervals is to be created,the T-LSP manager 202 reserves in the T-TED 206 bandwidths on every linkin each of the time intervals along the path for the LSP. When atemporal LSP with a number of time intervals is deleted, the T-LSPmanager 202 releases bandwidths on every link in each of the timeintervals along the path for the LSP. When a link is torn down, thetraffic engineering (TE) information corresponding to the link isremoved from the T-TED 206. When a link in the network is up, the TEinformation corresponding to the link is added into the T-TED 206.

The T-LDB 208 is configured to maintain a status of labels in the timeintervals for each node 221, 222 and link 231 in the network 230. TheT-LDB 208 is operably coupled to the T-LSP manager 202 through aninterface (Ic). The T-LDB 208 is also configured to reserve labels forthe links 231 during the time intervals upon request by the T-LSPmanager 202. In an embodiment, the T-LDB 208 is also operably coupled tothe network 230 through interface (In).

In an embodiment, the T-LDB 208 may be updated by the following events.When a temporal LSP with a number of time intervals is to be created,the T-LSP manager 202 reserves in the T-LDB 208 a label for every linkin each of the time intervals along the path for the LSP. For a nodespecific label space, a label on the downstream node is assigned for thelink. For a link specific label space, a label on the link is assignedfor the link. When a temporal LSP with a number of time intervals isdeleted, the T-LSP manager 202 releases the label for every link in eachof the time intervals along the path for the LSP. When a node in thenetwork is down, the label resources on the node is removed from theT-LDB 208 if a node specific label space is used. When a link in thenetwork is down, the label resources on the link is removed from theT-LDB 208 if a link specific label space is used. When a node in thenetwork is up, the label resources on the node is added into the T-LDB208 if a node specific label space is used. When a link in the networkis up, the label resources on the link is added into the T-LDB 208 if alink specific label space is used.

The T-LSPDB 212 is configured to store the time intervals, the set ofconstraints, the labels, the bandwidth, and the status for each LSP. TheT-LSPDB 212 is operably coupled to the T-LSP manager 202 through aninterface (Id). In an embodiment, the T-LDB 208 is also operably coupledto the network 230 through interface (In).

The network interface (In) is the interface between the T-SDN controller210 and the network 230. In an embodiment, the network interface (In) isan application programming interface (API) to the network 230. In anembodiment, the network interface (In) utilizes a Path ComputationElement (PCE) Communication Protocol (PCEP), a PCEP+, or any othersuitable protocol for facilitating communication between the T-SDNcontroller 210 and the network 230 as would be recognized by one skilledin the art upon reviewing this disclosure.

The network interface (In) permits the T-LSP manager 202 to communicatewith the nodes 221, 222, in the network 230 to establish a temporal LSPalong the path as computed. In an embodiment, the temporal LSP is set upat a start of each of the time intervals and deleted at an end of eachof the time intervals. In an embodiment, the temporal LSP is set upprior to or at a start of a first of the time intervals, the bandwidthis updated for each of the time intervals, and the LSP is deleted at anend of a last of the time intervals.

FIG. 3 is a schematic diagram of an embodiment of a SDN system 300including a T-SDN controller 310 configured to manage a network 330. Theschematic diagram depicts a centralized model for multiple domains. TheSDN system 300, the T-SDN controller 310, and the network 330 in FIG. 3are similar to the SDN system 100, 200, the SDN controller 110, 210, andthe network 130, 230 of FIGS. 1-2. As shown, the network 330 contains aplurality of edge nodes 321 and internal nodes 322 connected by links331. The edge nodes 321, the internal nodes 322, and links 331 of FIG. 3are similar to the edge nodes 121, 221, the internal nodes 122, 222, andlinks 131, 231 of FIGS. 1-2.

In an embodiment, the T-SDN controller 310 is configured to establish atemporal LSP through the network 330 and at least one other network(e.g., an adjacent network). To do so, the T-SDN controller 310communicates with the edge nodes 321 and the internal nodes 322 via aplurality of communication channels 340. The T-SDN controller 310includes a T-LSP manager 302, a T-PCE 304, a T-TED 306, a T-LDB 308, aT-LSPDB 312, and a network interface (In). The T-LSP manager 302, theT-TED 306, the T-LDB 308, and the T-LSPDB 312 of FIG. 3 are similar tothe T-LSP manager 202, the T-TED 206, the T-LDB 208, and the T-LSPDB 212of FIG. 2. Therefore, the details of these elements will not be repeatedfor the sake of brevity. The T-PCE 304 may be generically referred to asa temporal path element.

Because the T-SDN controller 310 of FIG. 3 includes the T-PCE 304instead of the T-CSPF 204 of FIG. 2, a temporal path through multipledomains (e.g., networks) may be computed. When a path request isreceived by the T-LSP manager 302, the T-PCE 304 communicates withanother T-PCE in another network via an interface (Im). Thiscommunication permits an end-to-end temporal LSP to be establishedthrough the multiple domains. In an embodiment, if the path requestreceived by the T-LSP manager 302 calls for a path through a singledomain, the T-PCE 304 may utilize a T-CSPF incorporated in the T-PCE 304to obtain a path for the LSP.

FIG. 4 is a schematic diagram of an embodiment of a SDN system 400including a T-SDN controller 410 configured to manage a network 430. Theschematic diagram depicts a hybrid model for a single domain with oneset of databases. The SDN system 400, the T-SDN controller 410, and thenetwork 430 in FIG. 4 are similar to the SDN system 100, 200, 300, theSDN controller 110, 210, 310, and the network 130, 230, 330 of FIGS.1-3. As shown, the network 430 contains a plurality of edge nodes 421and internal nodes 422 connected by links 431. The edge nodes 421, theinternal nodes 422, and links 431 of FIG. 4 are similar to the edgenodes 121, 221, 321, the internal nodes 122, 222, 322, and links 131,231, 331 of FIGS. 1-3.

In an embodiment, the T-SDN controller 410 is configured to establish atemporal LSP through the network 430. To do so, the T-SDN controller 410communicates with the edge nodes 421 and the internal nodes 422 via aplurality of communication channels 440. The T-SDN controller 410includes a T-LSP manager 402, a T-CSPF element 404, a T-TED 406, aT-LSPDB 412, and a network interface (In). In the embodiment of FIG. 4,the T-SDN controller 410 does not include a T-LDB. The T-LSP manager402, the T-TED 406, and the T-LSPDB 412 of FIG. 4 are similar to theT-LSP manager 202, 302, the T-TED 206, 306, and the T-LSPDB 212, 312 ofFIGS. 2-3. Therefore, the details of these elements will not be repeatedfor the sake of brevity.

Because the T-SDN controller 410 of FIG. 4 does not include a T-LDB, thenodes (e.g., the edge nodes 421) in the network 430 maintain the labels.In addition, no label information is stored in the T-LSPDB 412. In anembodiment, T-LSP manager 402 requests that the edge nodes 421 establishthe temporal LSP along the path as computed by exchanging PATH and RESVmessages with other nodes in the network using resource reservationprotocol traffic engineering (RSVP-TE). The RSVP is described in furtherdetail in Internet Engineering Task Force (IETF) document Request forComments (RFC) 2205 entitled “Resource ReSerVation Protocol (RSVP),” byR. Braden, et al., dated September 1997, which is incorporated herein byreference.

FIG. 5 is a schematic diagram of an embodiment of a SDN system 500including a T-SDN controller 510 configured to manage a network 530. Theschematic diagram depicts a hybrid model for a single domain with twosets of databases and communication with edge nodes 521. The SDN system500, the T-SDN controller 510, and the network 530 in FIG. 5 are similarto the SDN system 100, 200, 300, 400, the SDN controller 110, 210, 310,410, and the network 130, 230, 330, 430 of FIGS. 1-4. As shown, thenetwork 530 contains a plurality of edge nodes 521 and internal nodes522 connected by links 531. The edge nodes 521, the internal nodes 522,and links 531 of FIG. 5 are similar to the edge nodes 121, 221, 321,421, the internal nodes 122, 222, 322, 422, and links 131, 231, 331, 431of FIGS. 1-4.

In an embodiment, the T-SDN controller 510 is configured to establish atemporal LSP through the network 530. To do so, the SDN controller 510communicates with the edge nodes 521 via a plurality of communicationchannels 540. In an embodiment, the SDN controller 510 does not utilizethe internal nodes 522 in establishing the temporal LSP. The T-SDNcontroller 510 includes a T-LSP manager 502, a T-CSPF element 504, aT-TED 506, a T-LSPDB 512, and a network interface (In). The T-LSPmanager 502, the T-CSPF 504, the T-TED 506, and the T-LSPDB 512 of FIG.5 are similar to the T-LSP manager 202, 302, 402, the T-CSPF 204, 404,the T-TED 206, 306, 406, and the T-LSPDB 212, 312, 412 of FIGS. 2-4.Therefore, the details of these elements will not be repeated for thesake of brevity.

As shown, the T-SDN controller 510 of FIG. 5 also includes a regular ornormal LSP manager 502′. The normal LSP manager 502′ is operably coupledto a CSPF element 504′, a TED 506′, a LSPDB 512′, and a networkinterface (I′n). As such, the LSP manager 502′ is configured toestablish an LSP without the time intervals corresponding to the path ascomputed. In other words, the T-SDN controller 510 includes a T-LSPmanger 502 configured to establish a temporal LSP and a normal LSPmanager 502′ configured to establish an LSP. The temporal LSP and thenormal LSP may be used concurrently to transport traffic through thenetwork 530.

FIG. 6 is a schematic diagram of an embodiment of a SDN system 600including a T-SDN controller 610 configured to manage a network 630. Theschematic diagram depicts a hybrid model for a single domain with twosets of databases and communication with both edge nodes 621 andinternal nodes 622. In an embodiment, all nodes in the network 630 aremanaged. The SDN system 600, the SDN controller 610, and the network 630in FIG. 6 are similar to the SDN system 100, 200, 300, 400, 500, the SDNcontroller 110, 210, 310, 410, 510, and the network 130, 230, 330, 430,530 of FIGS. 1-5. As shown, the network 630 contains a plurality of edgenodes 621 and internal nodes 622 connected by links 631. The edge nodes621, the internal nodes 622, and links 631 of FIG. 6 are similar to theedge nodes 121, 221, 321, 421, 521, the internal nodes 122, 222, 322,422, 522, and links 131, 231, 331, 431, 531 of FIGS. 1-5.

Initially, a portion of network resources such as link bandwidth isallocated for the temporal LSPs and stored in the T-TED 506, anotherportion of network resources is allocated for the normal LSPs and storedin the TED 506′. In a first embodiment, a percentage of the networkresources such as seventy percent of the link bandwidth for every link531 is configured on the T-SDN controller for the temporal LSPs andstored in the T-TED 506 when the T-SDN controller starts, anotherpercentage of the network resources such as twenty percents of the linkbandwidth for every link 531 is configured on the T-SDN controller forthe normal LSPs and stored in the TED 506′.

In a second embodiment, an amount of the network resources such as 10 GBlink bandwidth for every link 531 is configured on the T-SDN controllerfor the temporal LSPs and stored in the T-TED 506 when the T-SDNcontroller starts, another amount of the network resources such as therest link bandwidth for every link 531 is configured on the T-SDNcontroller for the normal LSPs and stored in the TED 506′.

In a third embodiment, when the T-SDN controller starts, a portion ofthe network resources such as sixty percent of the link bandwidth forevery link 531 is configured on the T-SDN controller for the temporalLSPs and stored in the T-TED 506, the rest portion of the networkresources such as forty percent of the link bandwidth for every link 531is implied for the normal LSPs and stored in the TED 506′.

In an embodiment, the T-SDN controller 610 is configured to establish atemporal LSP through the network 630. To do so, the SDN controller 610communicates with the edge nodes 621 and the internal nodes 622 via aplurality of communication channels 640. The T-SDN controller 610includes a T-LSP manager 602 and an LSP manager 602′, a T-CSPF element604 and a CSPF element 604′, a T-TED 606 and a TED 606′, a T-LDB 608, aT-LSPDB 612 and a LSPDB 612′, and a network interface (In) and a networkinterface (I′n). The T-LSP manager 602 and an LSP manager 602′, theT-CSPF element 604 and the CSPF element 604′, the T-TED 606 and the TED606′, the T-LDB 608, the T-LSPDB 612 and the LSPDB 612′, and the networkinterface (In) and the network interface (I′n) of FIG. 6 are similar tothe T-LSP manager 502 and the LSP manager 502′, the T-CSPF element 504and the CSPF element 504′, the T-TED 506 and the TED 506′, the T-LSPDB512 and the LSPDB 512′, and the network interface (In) and the networkinterface (I′n) of FIG. 5. In addition, the T-LDB 608 is similar to theT-LDB 208, 308 of FIGS. 2-3. Therefore, the details of these elementswill not be repeated for the sake of brevity.

The T-LSP manager 602 is configured to establish a temporal LSP, whilethe LSP manager 502′ is configured to establish an LSP without the timeintervals. The temporal LSP and the normal LSP may be used concurrentlyto transport traffic through the network 630. Like the T-LDB 208, 308 inFIGS. 2-3, the T-LDB 608 is configured to maintain a status of labels inthe time intervals for each node 621, 622 and link 631 in the network630.

Initially, a portion of network resources including label resources isallocated for the temporal LSPs and stored in the T-TED 606 and T-LDB608, another portion of network resources is allocated for the normalLSPs and stored in the TED 606′. In a first embodiment, when the T-SDNcontroller starts, a percentage of the bandwidth resources such as sixtypercents of the link bandwidth for every link 631 is configured on theT-SDN controller and stored in the T-TED 606, a range of the label spacesuch as from 2000 to 80000 for every node 621 and 622 is configured forthe temporal LSPs on the T-SDN controller and stored in the T-LDB 608,and the same range of the label space for every node 621 and 622 is alsoconfigured on the node and stored in the node; another percentage of thebandwidth resources such as thirty percents of the link bandwidth forevery link 631 is configured for the normal LSPs and stored in the TED606′, and the rest range of the label space for every node 621 and 622is used for the normal LSPs on the node.

In a second embodiment, when the T-SDN controller starts, an amount ofthe bandwidth resources such as 50 GB link bandwidth for every link 631is configured on the T-SDN controller for the temporal LSPs and storedin the T-TED 606, a range of the label space for every node 621 and 622is configured for the temporal LSPs on the T-SDN controller and storedin the T-LDB 608, and the same range of the label space for every node621 and 622 is also configured on the node and stored in the node;another amount of the bandwidth resources such as the rest linkbandwidth for every link 631 is configured on the T-SDN controller forthe normal LSPs and stored in the TED 606′, and the rest range of thelabel space for every node 621 and 622 is used for the normal LSPs onthe node.

In a third embodiment, when the T-SDN controller starts, a portion ofthe bandwidth resources such as seventy percent of the link bandwidthfor every link 631 is configured for the temporal LSPs on the T-SDNcontroller and stored in the T-TED 606, a range of the label space suchas from 1000 to 90000 for every node 621 and 622 is configured for thetemporal LSPs on the T-SDN controller and stored in the T-LDB 608, andthe same range of the label space for every node 621 and 622 is alsoconfigured on the node and stored in the node; the rest portion of thebandwidth resources such as thirty percent of the link bandwidth forevery link 631 is implied for the normal LSPs and stored in the TED606′, and the rest range of the label space for every node 621 and 622is implied for the normal LSPs on the node.

FIG. 7 is a schematic diagram of an embodiment of a SDN system 700including a T-SDN controller 710 configured to manage a network 730. Theschematic diagram depicts a hybrid model for multiple domains. The SDNsystem 700, the T-SDN controller 710, and the network 730 in FIG. 7 aresimilar to the SDN system 300, the T-SDN controller 310, and the network330 of FIG. 3 except that the T-SDN controller 710 does not contain aT-LDB. As shown, the network 730 contains a plurality of edge nodes 721and internal nodes 722 connected by links 731. The edge nodes 721, theinternal nodes 722, and links 731 of FIG. 7 are similar to the edgenodes 321, the internal nodes 322, and links 331 of FIG. 3.

In an embodiment, the T-SDN controller 710 is configured to establish atemporal LSP through the network 730 and at least one other network(e.g., an adjacent network). To do so, the T-SDN controller 710communicates with the edge nodes 721 and the internal nodes 722 via aplurality of communication channels 740. The T-SDN controller 710includes a T-LSP manager 702, a T-PCE 704, a T-TED 706, a T-LSPDB 712,and a network interface (In). The T-LSP manager 702, the T-TED 706, andthe T-LSPDB 712 of FIG. 7 are similar to the T-LSP manager 302, theT-TED 306, and the T-LSPDB 312 of FIG. 3. Therefore, the details ofthese elements will not be repeated for the sake of brevity.

Because the T-SDN controller 710 of FIG. 7 includes the T-PCE 704, atemporal path through multiple domains (e.g., networks) may be computed.When a path request is received by the T-LSP manager 702, the T-PCE 704communicates with another T-PCE in another network via an interface(Im). This communication permits an end-to-end temporal LSP to beestablished through the multiple domains. In an embodiment, if the pathrequest received by the T-LSP manager 702 calls for a path through asingle domain, the T-PCE 704 may utilize a T-CSPF incorporated in theT-PCE 704 to obtain a path for the LSP. Because the T-SDN controller 710of FIG. 7 does not include a T-LDB, the nodes (e.g., the edge nodes 721)in the network 730 maintain the labels. In addition, no labelinformation is stored in the T-LSPDB 712.

FIG. 8 is a schematic diagram of an embodiment of network node 800. Thenetwork node 800 is similar to the edge nodes 121-721 and the internalnodes 122-722 in FIGS. 1-7. In an embodiment, the network node 800 isany device (e.g., an access point, an access point station, a router, aswitch, a gateway, a bridge, a server, a client, a user-equipment, amobile communications device, etc.) which transports data through anetwork, system, and/or domain. The schematic diagram of FIG. 8 depictsa distributed model for managing a temporal LSP. In the distributedmodel, a network node (e.g., an ingress node for a LSP tunnel)establishes the temporal LSP instead of the temporal LSP being set-up bya SDN controller (e.g., T-SDN controller 210). The network node 800 maybe referred to as a temporal network node.

As shown, the network node 800 includes a temporal MPLS (T-MPLS) element850, a T-TED 806, and a protocol element 854. In an embodiment, theprotocol element 854 is a temporal open shortest path first (T-OSPF)element. In an embodiment, the protocol element 854 is a temporalIntermediate System to Intermediate System (T-ISIS) element. The T-MPLS850 contains a T-LSP manager 802, a T-CSPF element 804, a T-LSPDB 812,and a temporal resource reservation protocol traffic engineering(T-RSVP-TE) element 852. The T-LSP manager 802, the T-CSPF element 804,the T-TED 806, and the T-LSPDB 812 of FIG. 8 are similar to the T-LSPmanager 202, the T-CSPF element 204, the T-TED 206, and the T-LSPDB 212of FIG. 2. Therefore, the details of these elements will not be repeatedfor the sake of brevity.

After a path has been computed and provided to the T-LSP manager 802 aspreviously described herein, the T-LSP manager 802 stores the intervalsand the set of constraints in the T-LSPDB 812. The T-LSP manager 802also sends a request to the T-RSVP-TE element 852 to initiate the set-upof an LSP (e.g., LSP tunnel). The request is sent to the T-RSVP-TEelement 852 via interface (Ir). In an embodiment, the T-RSVP-TE element852 exchanges PATH and RESV messages with other nodes in the network inorder to set up the LSP corresponding to the time intervals and the setof constraints.

Once bandwidth has been reserved by the network node 800 to facilitatethe temporal LSP satisfying the time intervals and the set ofconstraints, the bandwidth on the links between nodes will be changed.Those changed bandwidths are distributed to the protocol element 854 viainterface (In) coupled to the protocol element 854. In other words, theprotocol element 854 distributes bandwidth changes in the network. Forexample, the protocol element 854 distributes current link bandwidth toadjacent nodes. In an embodiment, the bandwidth changes are stored inthe T-TED 806 via interface (Ig).

FIG. 9 is a method 900 for establishing a temporal label switched path(T-LSP) implemented in a node (e.g., network node 800) in a network. Themethod 900 may be performed when a temporal LSP is to be establishedthrough a network. The network may be similar to the network 230 of FIG.2. At step 902, a T-LSP manager of the network node receives a pathrequest. The T-LSP manager may be similar to the T-LSP manager 202 inFIG. 2. The path request includes, for example, time intervals and a setof constraints. At step 904, a T-CSPF element of the network nodeobtains traffic engineering information from a T-TED. The T-CSPF elementmay be similar to the T-CSPF element 204 in FIG. 2. At step 906, theT-CSPF computes a path satisfying the time intervals and the set ofconstraints based on the traffic engineering information obtained. Atstep 908, T-CSPF element provides the path as computed to the T-LSPmanager.

At step 910, the T-LSP manager of the network node requests a T-RSVP-TEelement to establish the temporal LSP along the path as computed. TheT-RSVP-TE element is able to establish the temporal LSP along the pathby exchanging PATH and RESV messages with other nodes in the network.Such other nodes include, for example, intermediate or internal nodesand an egress nodes in the network. In an embodiment, the time intervalsand the set of constraints are stored in a T-LSPDB operably coupled tothe T-LSP manager after the path has been computed. The T-LSPDB may besimilar to the T-LSPDB 212 in FIG. 2. In an embodiment, the current linkbandwidth is distributed to the other nodes in the network and changesin the current link bandwidth are stored in the T-TED. The T-TED may besimilar to the T-TED 206 in FIG. 2.

At least some of the features/methods described in this disclosure areimplemented in a network element (e.g., one of the T-SDN-controllers210-710 or the network node 800). For instance, the features/methods ofthis disclosure may be implemented using hardware, firmware, and/orsoftware installed to run on hardware. FIG. 10 is a schematic diagram ofan embodiment of a network element 1000 that may be used to transportand process traffic through at least a portion of a network, such asnetwork 230, shown in FIG. 2. The network element 1000 is any device(e.g., an access point, an access point station, a router, a switch, agateway, a bridge, a server, a client, a user-equipment, a mobilecommunications device, etc.) which transports data through a network,system, and/or domain. Moreover, the terms network element, networknode, network component, network module, network controller, and/orsimilar terms may be interchangeably used to generally describe anetwork device and do not have a particular or special meaning unlessotherwise specifically stated and/or claimed within the disclosure.

The network element 1000 comprises one or more downstream ports 1010coupled to a transceiver (Tx/Rx) 1020, which comprise transmitters,receivers, or combinations thereof. The Tx/Rx 1020 transmits and/orreceives frames from other network nodes via the downstream ports 1010.Similarly, the network element 1000 comprises another Tx/Rx 1020 coupledto a plurality of upstream ports 1040, wherein the Tx/Rx 1020 transmitsand/or receives frames from other nodes via the upstream ports 1040. Thedownstream ports 1010 and/or the upstream ports 1040 include electricaland/or optical transmitting and/or receiving components. In anotherembodiment, the network element 1000 comprises one or more antennascoupled to the Tx/Rx 1020. The Tx/Rx 1020 transmits and/or receives data(e.g., packets) from other network elements via wired or wirelessconnections, depending on the embodiment.

A processor 1030 is coupled to the Tx/Rx 1020 and is configured toprocess the frames and/or determine to which nodes to send (e.g.,transmit) the packets. In an embodiment, the processor 1030 comprisesone or more multi-core processors and/or memory modules 1050, whichfunction as data stores, buffers, etc. The processor 1030 is implementedas a general processor or as part of one or more application specificintegrated circuits (ASICs), field-programmable gate arrays (FPGAs),and/or digital signal processors (DSPs). Although illustrated as asingle processor, the processor 1030 is not so limited and may comprisemultiple processors. The processor 1030 is configured to communicateand/or process multi-destination frames.

FIG. 10 illustrates that a memory module 1050 is coupled to theprocessor 1030 and is a non-transitory medium configured to storevarious types of data and/or instructions. Memory module 1050 comprisesmemory devices including secondary storage, read-only memory (ROM), andrandom-access memory (RAM). The secondary storage is typically comprisedof one or more disk drives, optical drives, solid-state drives (SSDs),and/or tape drives and is used for non-volatile storage of data and asan over-flow storage device if the RAM is not large enough to hold allworking data. The secondary storage is used to store programs which areloaded into the RAM when such programs are selected for execution. TheROM is used to store instructions and perhaps data that are read duringprogram execution. The ROM is a non-volatile memory device whichtypically has a small memory capacity relative to the larger memorycapacity of the secondary storage. The RAM is used to store volatiledata and perhaps to store instructions. Access to both the ROM and RAMis typically faster than to the secondary storage.

The memory module 1050 is used to house the instructions for carryingout the various embodiments described herein. In one embodiment, thememory module 1050 comprises a temporal LSP module 1060 which isimplemented via execution by the processor 1030. In an alternateembodiment, the processor 1030 comprises the temporal LSP module 1060.In one embodiment, the temporal LSP module 1060 is implemented accordingto embodiments of the present disclosure to perform temporal LSP tunnelservices in an MPLS network, such as network 100. In an alternateembodiment, the temporal LSP module 1060 may be implemented on differentnetwork elements (e.g., a SDN controller or a network node) or across aplurality of network elements (NEs). In an embodiment, temporal LSPmodule 1060 implements method 900 of FIG. 9. In addition, networkelement 1000 may comprise any other means for implementing the temporalLSP module as would be appreciated by one skilled in the art upon reviewof this disclosure.

It is understood that by programming and/or loading executableinstructions onto the network element 1000, at least one of theprocessors 1030, the cache, and the long-term storage are changed,transforming the network element 1000 in part into a particular machineor apparatus, for example, a multi-core forwarding architecture havingthe novel functionality taught by the present disclosure. It isfundamental to the electrical engineering and software engineering artsthat functionality that can be implemented by loading executablesoftware into a computer can be converted to a hardware implementationby well-known design rules known in the art. Decisions betweenimplementing a concept in software versus hardware typically hinge onconsiderations of stability of the design and number of units to beproduced rather than any issues involved in translating from thesoftware domain to the hardware domain. Generally, a design that isstill subject to frequent change may be preferred to be implemented insoftware, because re-spinning a hardware implementation is moreexpensive than re-spinning a software design. Generally, a design thatis stable and will be produced in large volume may be preferred to beimplemented in hardware (e.g., in an ASIC) because for large productionruns the hardware implementation may be less expensive than softwareimplementations. Often a design may be developed and tested in asoftware form and then later transformed, by well-known design rulesknown in the art, to an equivalent hardware implementation in an ASICthat hardwires the instructions of the software. In the same manner as amachine controlled by a new ASIC is a particular machine or apparatus,likewise a computer that has been programmed and/or loaded withexecutable instructions may be viewed as a particular machine orapparatus.

Any processing of the present disclosure may be implemented by causing aprocessor (e.g., a general purpose multi-core processor) to execute acomputer program. In this case, a computer program product can beprovided to a computer or a network device using any type ofnon-transitory computer readable media. The computer program product maybe stored in a non-transitory computer readable medium in the computeror the network device. Non-transitory computer readable media includeany type of tangible storage media. Examples of non-transitory computerreadable media include magnetic storage media (such as floppy disks,magnetic tapes, hard disk drives, etc.), optical magnetic storage media(e.g., magneto-optical disks), compact disc read-only memory (CD-ROM),compact disc recordable (CD-R), compact disc rewritable (CD-R/W),digital versatile disc (DVD), Blu-ray (registered trademark) disc (BD),and semiconductor memories (such as mask ROM, programmable ROM (PROM),erasable PROM, flash ROM, and RAM). The computer program product mayalso be provided to a computer or a network device using any type oftransitory computer readable media. Examples of transitory computerreadable media include electric signals, optical signals, andelectromagnetic waves. Transitory computer readable media can providethe program to a computer via a wired communication line (e.g., electricwires, and optical fibers) or a wireless communication line.

In an embodiment, the T-SDN controller (e.g., the T-SDN controller 210)is configured as a temporal stateful PCE (T-Stateful-PCE) controller. Insuch an embodiment, the T-SDN may include, for example, a T-LSP manager,a T-PCE, a T-TED, and a T-LSPDB configured to function like similarlyidentified components herein. After obtaining the path for the LSP, theT-Stateful-PCE controller is configured to reserve the TE resources(e.g., link bandwidths for the LSP along the path in each of the timeintervals) in the T-TED, update the information about the LSP in theT-LSPDB, initiate the creation of the LSP at the start of each timeinterval by sending a Path Computation LSP Initiate Request (PCInitiate)message to the ingress of the LSP, and deleting the LSP at the end ofeach time interval by sending another PCInitiate message with a remove(R) flag set to a binary number (e.g., 1). The T-Stateful-PCE controllerupdates the information about the LSP in the T-LSPDB accordingly afterreceiving a Path Computation LSP State Report (PCRpt) message from theingress of the LSP.

Disclosed herein is a temporal software defined network (T-SDN)controller configured to manage a network containing a plurality ofnodes connected by links. The controller includes first means forreceiving a path request, wherein the path request includes timeintervals and a set of constraints. The controller includes a secondmeans for receiving the path request from the first means, means forobtaining traffic engineering information. The controller also includesmeans for computing a path satisfying the time intervals and the set ofconstraints based on the traffic engineering information obtained, andmeans for providing the path as computed to the first means forreceiving the path request, means for providing the traffic engineeringinformation to the second means for use in computing the path uponrequest by the second means for receiving the path request, and meansfor reserving bandwidth corresponding to the path during the timeintervals upon request by the first means for receiving the pathrequest. The controller also includes means for reserving labels for thelinks during the time intervals upon request by the first means forreceiving the path request, means for storing the time intervals, theset of constraints, the labels, and the bandwidth, and means forpermitting the first means for receiving the path request to communicatewith the nodes in the network to establish a temporal LSP along the pathas computed.

Disclosed herein is a temporal software defined network (T-SDN)controller configured to manage a network containing a plurality ofnodes connected by links. The controller includes first means forreceiving a path request, wherein the path request includes timeintervals and a set of constraints. The controller also includes secondmeans for receiving the path request from the first means for receivingthe path request, means for obtaining traffic engineering information,means for computing a path satisfying the time intervals and the set ofconstraints based on the traffic engineering information obtained, andmeans for providing the path as computed to the first means forreceiving the path request. The controller also includes means forproviding the traffic engineering information to the second means forreceiving the path request for use in computing the path upon request bythe second means for receiving the path request, and means for reservingbandwidth corresponding to the path during the time intervals uponrequest by the first means for requesting the path request, means forstoring the time intervals, the set of constraints, and the bandwidth,and means for permitting the first means for receiving the path requestto instruct an ingress node in the network to establish a temporal LSPalong the path as computed.

Disclosed herein is a method for establishing a temporal label switchedpath (T-LSP) implemented in a node in a network including means forreceiving a path request including time intervals and a set ofconstraints, means for obtaining traffic engineering information from atemporal traffic engineering database (T-TED), means for computing apath satisfying the time intervals and the set of constraints based onthe traffic engineering information obtained, means for providing thepath as computed to the means for obtaining, and means for requesting atemporal resource reservation protocol traffic engineering (T-RSVP-TE)means to establish the temporal LSP along the path as computed byexchanging PATH and RESV messages with other nodes in the network.

While several embodiments have been provided in the present disclosure,it should be understood that the disclosed systems and methods might beembodied in many other specific forms without departing from the spiritor scope of the present disclosure. The present examples are to beconsidered as illustrative and not restrictive, and the intention is notto be limited to the details given herein. For example, the variouselements or components may be combined or integrated in another systemor certain features may be omitted, or not implemented.

In addition, techniques, systems, subsystems, and methods described andillustrated in the various embodiments as discrete or separate may becombined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as coupled or directly coupled orcommunicating with each other may be indirectly coupled or communicatingthrough some interface, device, or intermediate component whetherelectrically, mechanically, or otherwise. Other examples of changes,substitutions, and alterations are ascertainable by one skilled in theart and could be made without departing from the spirit and scopedisclosed herein.

What is claimed is:
 1. A method for establishing a temporal labelswitched path (LSP) implemented in a controller in a network,comprising: receiving a path request including a time interval and a setof constraints; obtaining traffic engineering information from a firstdatabase; computing, by the controller, a path satisfying the timeinterval and the set of constraints based on the traffic engineeringinformation obtained; storing the time interval and the set ofconstraints in a second database; and instructing an ingress node of thetemporal LSP to signal the temporal LSP in the network along the pathcomputed at a start of the time interval identified in the path requestand to tear down the temporal LSP at an end of the time intervalidentified in the path request, wherein the temporal LSP crossesmultiple domains, and wherein each of the multiple domains is controlledby a separate controller.
 2. The method of claim 1, further comprisingdistributing current link bandwidth to other nodes and storing changesin the current link bandwidth in the first database.
 3. The method ofclaim 1, wherein the traffic engineering information comprises abandwidth for each link in the network corresponding to the timeinterval.
 4. The method of claim 1, wherein the first database is atemporal traffic engineering database (T-TED).
 5. The method of claim 1,wherein the second database is a temporal LSP database (T-LSPDB).
 6. Themethod of claim 1, further comprising establishing an LSP without thetime interval corresponding to the path as computed.
 7. The method ofclaim 1, wherein the controller is a temporal software defined network(T-SDN) controller.
 8. The method of claim 1, further comprisingreceiving the path request from a network administrator.
 9. The methodof claim 1, further comprising receiving the path request from anapplication.
 10. A controller configured to establish a temporal labelswitched path (LSP), the controller comprising: a memory storagecomprising instructions; and a processor in communication with thememory, wherein the processor executes the instructions to cause thecontroller to: receive a path request including a time interval and aset of constraints; obtain traffic engineering information from a firstdatabase; compute a path satisfying the time interval and the set ofconstraints based on the traffic engineering information obtained; storethe time interval and the set of constraints in a second database; andinstruct an ingress node of the temporal LSP to signal the temporal LSPin a network along the path computed at a start of the time intervalidentified in the path request and to tear down the temporal LSP at anend of the time interval identified in the path request, wherein thetemporal LSP crosses multiple domains, and wherein each of the multipledomains is controlled by a separate controller.
 11. The controller ofclaim 10, wherein the processor executes the instructions to cause thecontroller to distribute current link bandwidth to other nodes and storechanges in the current link bandwidth in the first database.
 12. Thecontroller of claim 10, wherein the traffic engineering informationcomprises a bandwidth for each link in the network corresponding to thetime interval.
 13. The controller of claim 10, wherein the firstdatabase is a temporal traffic engineering database (T-TED).
 14. Thecontroller of claim 10, wherein the second database is a temporal LSPdatabase (T-LSPDB).
 15. The controller of claim 10, wherein theprocessor executes the instructions to cause the controller to establishan LSP without the time interval corresponding to the path as computed.16. The controller of claim 10, wherein the controller is a temporalsoftware defined network (T-SDN) controller.
 17. The controller of claim10, wherein the path request is received from a network administrator oran application.